Weeks 13-16

Unborn Baby Growth Milestones during Weeks 13-16

By the end of the 16th week, you can easily feel your grapefruit-sized uterus midway between your pubic bone and your navel. Let’s look at 10 unborn baby growth milestones during this month:

1. Your little “peach” is about the size of a peach!
2. Unborn baby growth doubles in length and nearly quadruples in weight.
3. She is around five inches long and weighs around four ounces at the end of the 16th week.
4. Her arms lengthen this month, and she can flex her arms, clasp her hands and suck her thumb. Her legs lengthen, and kicking intensifies (you probably don’t feel it yet).
5. Her bones (arms, hands and legs) form and are visible on x-ray or ultrasound.
6. Baby “breathes” amniotic fluid in and out through the developing air passages and tiny sacs in her lungs.
7. Her external ear folds are becoming more developed, as is her hearing, enabling her to react to sounds.
8. She develops her own unique fingerprints.
9. Blood vessels proliferate at a rapid rate and show through baby’s thin, still transparent skin.
10. The placenta becomes the prime producer of pregnancy hormones. You will continually need to nourish your baby and yourself, and your baby now free floats in her own bubble of amniotic fluid, contained in an amniotic sac. By the 16th week, there is enough amniotic fluid for doctors to safely enter the fluid-filled sac by a procedure called amniocentesis.